C CycloWizard Lifer Sep 10, 2001 12,348 1 81 Apr 16, 2009 #2 Because the sign convention you're using decided that's the way it should be?
H Howard Lifer Oct 14, 1999 47,982 11 81 Apr 16, 2009 #3 All my FBDs have random sign notations. Keeps the TAs on their toes.